Rajagopal Nagarajan

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We propose Interaction Categories as a new paradigm for the semantics of functional and concurrent computation. Interaction categories have speciications as objects , processes as morphisms, and interaction as composition. We introduce two key examples of interaction categories for concurrent computation and indicate how a general axiomatisation can be(More)
We define a language CQP (Communicating Quantum Processes) for modelling systems which combine quantum and classical communication and computation. CQP combines the communication primitives of the pi-calculus with primitives for measurement and transformation of quantum state; in particular, quantum bits (qubits) can be transmitted from process to process(More)
Many diierent notions of \property of interest" and methods of verifying such properties arise naturally in programming. A general framework of \Speciication Structures" is presented for combining diierent notions and methods in a coherent fashion. This is then applied to concurrency in the setting of Interaction Categories. As an example, we present a type(More)
We present the SQRAM architecture for quantum computing, which is based on Knill’s QRAM model. We detail a suitable instruction set, which implements a universal set of quantum gates, and demonstrate the operation of the SQRAM with Deutsch’s quantum algorithm. The compilation of high-level quantum programs for the SQRAM machine is considered; we present(More)
We establish fundamental and general techniques for formal verification of quantum protocols. Quantum protocols are novel communication schemes involving the use of quantum-mechanical phenomena for representation, storage and transmission of data. As opposed to quantum computers, quantum communication systems can and have been implemented using present-day(More)
We define a language CQP (Communicating Quantum Processes) for modelling systems which combine quantum and classical communication and computation. CQP combines the communication primitives of the pi-calculus with primitives for measurement and transformation of quantum state; in particular, quantum bits (qubits) can be transmitted from process to process(More)
We propose a typed calculus of synchronous processes based on the structure of interaction categories. Our aim has been to develop a calculus for concurrency that is canonical in the sense that the typed-calculus is canonical for functional computation. We show strong connections between syntax, logic and semantics, analogous to the familiar correspondence(More)
We describe the use of quantum process calculus to describe and analyze quantum communication protocols, following the successful field of formal methods from classical computer science. The key idea is to define two systems, one modelling a protocol and one expressing a specification, and prove that they are behaviourally equivalent. We summarize the(More)
This paper presents a graph-based formulation of controlflow analysis using results from game semantics and proof-nets. Controlflow analysis aims to give a conservative prediction of the flow of control in a program. In our analysis, terms are represented by proof-nets and control-flow analysis amounts to the analysis of computation paths in the proof-net.(More)